Radio tuning device



Oct. 219, 1931. 1... H. MORIN RADIO TUNING DEVICE Filed July 12, 1929 4 Sheets-Sheet 1 M 42M ATTORNEY BY J L. H. MORIN RADIO TUNING DEVICE Oct. 20, 1931.

4 Sheets- Sheet 2 Filed July 12, 1929 JNVENTOR A'r'ToRNEY Oct. 20, 1931.

L. H. MORIN 1,828,197

RADIO TUNING DEVICE Filed July 12, 1929 4 Sheets-Sheet 3 61%,} 1K MINVENTOR W ATTORNEY Patented Oct 20; 1931 UNITED STATES PATENT OFFICE LOUIS H. Mom, 01 NEW YORK, N. Y., ASBIGNOB 'l'O DOEHLER DIE-CASTING 00., A

GORPPRATION OF NEW YORK RADIO. TUNING DEVICE Application filed duly 12, 1929. Serial No. 877,709.

My invention relates to automatic tuning devices for radio receiving sets and has an especial adaptation totuning devices of the general construction illustrated in my cogpending application Serial No. 355,190, although it is by no means restricted in its application to that form of automatic tuner.

By this invention I am able to dispense with the usual hand operated dials for tuning the set. Heretofore, the automatic tuning mechanisms have been additional tuning means supplementing the usual dial controls and serviceable only to tune the set to the particular selected stations, which are neces- 1 5 sarily restricted in number. The set could be tuned to other stations only by using the usual dial controls.

In accordance with my invention, a knob or other manual device is;employed in cooperation with the manually operated members of the automatic tuner to obtain the preselected settings of the automaictuner, and is also available tooperate the resonance-varying devices of the set throughout their entire range of adjustment. This knob, therefore, has the double function of controlling the selective settings of the automatic tuner and of operating the resonance-varying devices independently of the automatic tuner. But

two knobs, dials, or other form of manually operative devices are, therefore, necessary with the particular form of automatic tuner illustrated in my said copending application.

In that form of automatic tuner, the shaft whichis operatively connected to the movable art of the tuning element or resonancevarymg device has upon it a series of crank elements (specifically, single-toothed *pinions), which are independently adjustable to es any angular setting upon the shaft, aiidbetween these cranks are friction members which are non-rotative upon the shaft. The cranks and the friction members are squeezed together by a clamping nut in order to lock the cranks to the shaft,and a single manual operator is movable into selective engagement with the cranks in order to rotate the shaft to the proper angular positionto obtain the desired tuning of the instrument.

Thisclamping nut is operated by a knob which is available on the set for convenient manipulation. In the embodiment of my invention which I have chosen for illustration, some abutment, such as a pin,,washer, collar, or the like, is provided on the shaft behind the nut so that when the nut is backed away from clamping position, it comes into frictional enga ement with the abutment and is thereby loc ed to the shaft. In both its clamping and its unclamping positions, the

nut is, therefore, secured to the shaft a ainst independent rotation so that the operatlon of the knob will operate the resonance-varying devices.

When the clamping nut is locked to the shaft through the medium of the abutment, the crank members are released for independent rotation upon the shaft. It is possible, therefore, to et the an lar setting desired for each cran by moving the crank to the angular position which it occupies when it is operated by the manual, holding it'in this position while the shaft is turned by the knob until the set is tuned into resonance with the selected station. This same procedure can be followed with each one of the cranks and the nut is then set up by operating the knob until it assumes clamping osition and the cranks are locked to the sha thereafter, the actuation of any crank will brin the set into resonance with the station which that crank. represents. However, the knob, which is employed to obtain the settings of the cranks, is also available to tune the resonance-varying devices since it is operatively connected to the Zhaft through the cranks and friction memers.

The necessary lost motion is provided in the connections between the cranks and their manual operating members, and a stop is provided to limit the rotation of the shaft so that the nut may be turned independently of the shaft after the limit of movement of the shaft in each direction is reached.

This specific embodiment of my invention will'now be more particularly described in connection with the accompanying drawings,

tains the external parts of the tuning mechanlsm;

Fig. 2 is a side elevation of the mechanism with the side of the cabinet removed and the front panel irregularly sectioned;

Fig. 3 is an irregular section from front to rear on a somewhat enlarged scale;

Fig. 4 is a sectional elevation approximately on the line 44 of Fig. 3;

Fig. 5 is a section of the parts shown in F i 4, taken on the line 5-5;

Fig. 6 is a sectional elevation on the line 66 of Fig. 3;

Fig. 7 is a horizontal section of the device taken on the irregular lines 77 of Figs. 2 and 3.

The tuning mechanism is shown as situated within the cabinet 1 of a radio receivingset with the manually operated parts projecting through the front panel. By way of illustration, the tuning element is shown as a variable condenser 2 disposed above the tuning mechanism with its shaft 3 running p Through this connectlon the turning of the from front to rear of the cabinet and a pulley 4 on its shaft over which runs the belt 5 that is operated by the tuning mechanism. A

dial 6 of any usual or suitable construction, is

carried by the shaft 3 and is exposed through an opening 7 in the front panelto indicate the setting of the instrument.

The construction of the automatic tuning mechanism is in general the same as that shown in my said copending application Serial No. 355,190. The mechanism has two side plates or frame members 8 and 9, and a front plate 10. Journaled in these side plates is the main shaft 11, on the outer end of which is fixed two pulleys 12 and 13, to each of which one end of the belt 5 is attached in such manner that the shaft 11 may be given a rotation in either direction of something less than 360. Intermediate the pulley 4 of the pulleys 12 and 13, the belt runs over two idler pulleys 14. and 15, which are pivoted in brackets on the bottom of the cabinet and are disposed at such angles to the horizontal as properly to guide the belt 5. Through this connection the rotation of the shaft 11 is transmitted to the pulley L and to the movable part of the tuning, element 2.

The shaft 11 is provided with four keyways, and mounted upon the shaft are a plurahty, shown as ten, of actuating members, shown as cranks'or pinions which are numbered from 160 to 16 inclusive (see Fig. 6). These pinions are each provided with a single tooth '17 and are loosely mounted upon the shaft. Between the pinions are friction discs 18, and a friction disc is also provided at each end of the pack, the disc 18a bein at the left end in Fig. 6, and the friction isc 18b bein at the ri ht end. The engaging faces of t 0 discs and pinions are beveled, the pinions having a widened periphery and the discs having a narrowed periphery. In this .way the tooth 17 is made wider than the hub of the pinion so as to provide a fairly broad engaging face for the teeth on the driving gears.

A clamp nut 19 screws on the right end of the shaft 11, which is threaded for this purpose, and this nut is provided on its outer end with an integral spur gear 20, with which meshes a pinion 21 on the stub shaft 22. This stub shaft is disposed parallel to and in front of the main shaft 11 and bears at its outer end in the side frame 8 and at its inner end in a housing 23 formed on the inner face of the front plate 10. A bevelv gear 24 on the inner end of the stub shaft 22 within the housing 23 meshes with bevel gear 25 on a stem 26 which bears in the front and rear walls of the housing 23 and projects through the front plate 10. A knob 27 on this stem 26 affords means for manipulation of the gear train just described, the knob being in this manner brought to the central vertical line of the ane knob 27 serves to back off and screw 'up the clamping nut 19 and thereby release and clamp the pinions. Three coil springs 28, one of which is shown in Fig. 6, are seated in recesses in the inner face of the clamping nut 19 and these springs at all times bear against the outer face of a washer 29 on the shaft 11 immediately adjacent the friction disc 18?) and therefore serve to exert alight frictional pressure upon the ack even when the nut 19 is backed away. his ressure is to hold the pinions sufliciently in rictioiial engagement with the shaft to prevent their dis lacement accidentally during the setting 0 any one pinion, as will presently appear.

Back of the clamping nut 10 the shaft 11 has an abutment 30, which is shown as a collar fixed upon the shaft. This abutment permits of just enough travel of the nut to clamp and release the pinions. The engagement of the nut against the abutment 30 serves to lock the nut to the shaft against relative rotation. In this way. the knob 26 is connected to rotate the shaft 11 and hence the movable part of the tuning element 2 when the pinions are unclamped, and free to be turned upon the shaft 11. It will also be observed that when the nut is in its clamping position, it is frictionally locked to the shaft through the friction discs and pinions and that, therefore, the knob 27 may be employed to adjust the tuning element in both positions of the clamping nut.

The outer friction disc 180 has a lateral stop projection 180, which cooperates with' a web 9a on the inner face of the side plate 9 to limit the rotation of the shaft 11. When it is desired to back off the nut 19, the knob 27 is turned in the proper direction until the stop members 180 and 9a engage whereupon further rotation of the shaft 11 is prevented and the continued turningof the knob serves to feed the nut 'in a backward direction until it 'engages'the abutment 30. When the knob is thereafter turned in the opposite direction, the shaft 11 will turn with it due to the frictional engagement between the nut and the abutment until the shaft reaches its'opposite limit of movement. Thereafter, further turning of the knob will serve to feed the nut forward and clamp the pinions and friction discs together.

The manual operating'elements are shiftable into engagement selectively with any pne of the plnions. Theyare carried by a support which consists of a two-part casting 31.' This casting has a hub portion 32 at its front end which slides upon a transverse guide rod 33, and is also provided with aws 34 which slide upon a rear transverse rod 35.

This casting has a downward annular projection 36, which axiallysurrounds the shaft 11 and'the parts mounted thereon. The inner faces of the two halves of the casting are recessed and within this recess with their axes'in line with the annular part 36 of the casting are two annular gears 37 and 38, each gear having upon its outer lateral face a These two gears have their inner faces contiguous and together are slightly wider than the face of the pinion 16 and the tooth 17 thereon. Theouter periphery of the gears is provided with gear teeth and each gear has on its inner periphery-a single tooth 40. The

' inner diameter of the gears is such that the i so " both teeth 40 will strike the tooth 17 of any pinion.

as'they are rotated about that pinion.

On the upper part of thecasting 31 at the top of the recess between the ,two inner faces of the halves, is slidably disposed a rack 41, which runs from front to rear of the casting and has its front end protruding out through a horizontal slot '42 in the frontpanel of the cabinet. 43, back of which is an index pointer 44, the rear part of which extends through the'slot backof the knob and is secured to the front face of the casting. A cover plate is also secured to the front face of the casting back of the slot 42 and is of sufiicient length horizontally to close the slot in the rear and conc eal the parts behind it in both extremes of adjustment of the casting and of the knob 43. @The rack'41 has operative connection with gears 37 and 38, the width of the rack equaling the combined width of the. two gears.- This connection is, such that the movementof the rack rotates the two gears in opposite directions. For this purpose the rack is shown as geared to the gear 37 through asingle pinion 46 and as geared to the gear 38through the two pinions 47 and 48.

A convolute spring 49 serves to retract the rack '41'after is withdrawn by hand to ef- On this front end issecured a knob feet a tuning operation. This -sprin .is attaclied at oneend to the rear end of the rack; 41 and is bent around an idler pulley 50- on the rear of the casting and is connected at its other end to a pin on the casting below the jaws 34. w 7 I A decorative escutcheon plate 50 is disposed on the front of, the panel about the slot 42 and in this escutcheon plate immediately above the slot 42 there is secured a strip on which are marked the initials of the several stations to which the set may be automati" cally tuned. Back of this strip is a trans-v 53 register with the initials of the several stations and these notches are in direct alignment with the several inions 16. A guide strip 41a on the top 0 the rack 41 isof a height to enter these notches 52 when the rack is pulled out and the strip is of such a length that it terminates just back of the shaft 33 when the rack is retracted. The front end of the strip 41a is beveled or pointed so as to guide the strip into the slots 52 and thereby facilitate alignment ofthe gears 37 and 38 with the respective pinions.

Each pinion is set in proper position to bring the turning mechanism and the receiv- 9 ing circuit into resonance with the particular station which thepinion represents, in the followin manner: The knob 27 is turned so as to bac off the nut 19 and release the compression upon the elements on the shaft 11. he-springs 28 continue to exert a pressure upon the elements so as to hold the pinions against turning unless positive force is brought to bear upon them. If it be desired, for example, to set the pinion 16aso that-its actuation will tune the set to station WAAM, the knob 42 with the rack and other parts carried by the casting 31 are moved over to register with the slot 52registering with the station numerals WAAM, which is the position of the parts shown in the drawings except Fig. 1. The rack 41 is then withdrawn. This movement rotates the gears 37 and 38 in opposite directions and the teeth 40 cooperate to move the "tooth 17on the pinion 16a to the position where the teeth 40 meet. The pinion is thus locked in this position. Due to the release of the clamping pressure of the nut 19, the shaft 11 may now be turned within the pinion 16a and the pinion 16a will be restrained from rotation by enga ement of the teeth; 40 with the tooth 17. T e other pinions will, however, turn with the shaft without altering their angular relation thereto due to the pressure of the springs 28. In

its

engagement of the nut 19 and the abutment 30. When the set is tuned to station WAAM, the operator will release the rack and further turnin of the shaft 11 by the knob 27 will therea er carry the pinion 16a with the shaft without changing its angular relation thereto. The operator will, therefore, turn the knob until the shaft 11 reaches the limit of its movement, after which further turning of the knob will screw up the nut 19 and positively clam the pinion 16a to the shaft. The nut is there also locked to the shaft by reason of its flictional engagement with the washer 29, and the operator may use the knob 27 for tuning the set and at the same time the rack-operated parts may be used for automatically tuning the set to any one of the ten stations represented by the ten pinions.

It will be understood that the steps above described for setting the pinion 16a will be repeated with all of the other pinions, theset being tuned to the respective stations which the several pinions represent. Wheneverthe ars 37 and 38 are moved into register wit any pinion and the rack is withdrawn, that pinion will always be moved to the position which it occupied when it was set with respect to the shaft 11, and it will, therefore, always move the tuning element to the proper ition to attune the set to the station which it re resents.

It will be an erstood that myinvention is not limited to the particular embodiment illustrated and described, but that the principieithereof may be variously otherwise emied without departing from the scope of the invention, as expressed in the appended claims.

I claim:

,1. In a radio receiving set, a tuning element, a shaft connected to adjust the tuning element, a lurality of actuatin elements independent y angularly adjusta 1e on the shaft, common means for simultaneously locking and unlocking the actuating elements with respect to the shaft in any ad usted positions, manual means for selectively operating the actuating elements, a manual device for operating the locking means, and means to connect the manual device to the shaft when the actuating elements are unlocked.

2. In a radio receiving set, a tuning ele-.

ment, a shaft connected to adjust the tuning element, a plurality of crank'elements dison the shaft independently angularly adjustable thereon, manual means for selectively operating the crank elements having a'lost motion connection therewith, frictional clam ing means for securing the cranks to the sll aft in any adjusted sition, a manual device shiftable on'the s aft to operate the clamping means, and means for connecting the manual device to the shaft when retracted from clamping position. a

' 3. In a radio receiving set, atuning elelar y adjustable thereon, manual means selective y operating the crank elements having a lost motion connection therewith, friction means between the cranks secured to the shaft against relative angular movement and adapted when brought into lateral frictional engagement with the cranks to lock the cranks to the shaft, a clamping member on the shaft shiftable to clamp the friction means and cranks, a manual member for operating the clamping member, and means to lock the clampin member to the shaft when retracted to non-c amping position.

4. In a radio receiving set a tuning element, a shaft connected to ad ust the tuning element, a plurality of crank elements dis-. posed on the shaft independently angularly adjustable thereon, manual means for selectively operating the crank elements having a lost motion connection therewith, friction means between the cranks secured to the shaft against relative angular movement and adapted when brought into lateral frictional engagement with the. cranks to lock the cranks to the shaft, a clamping member on the shaft shiftable to clamp the friction means and cranks, a manual member for operating the clamping member, and an abutment on the shaft positioned to be engaged by the clamping member when retracted.

5. In a radio receiving set, a tuning element, a shaft operatively connected thereto,

a plurality of cranks on the shaft independently angularly adjustable thereon, a single manual operating member for the cranks.

slidable selectively into engagement therewith, a'nut' on the shaft operative to lock the cranks to the shaft, means to lock the nut against rotation on the shaft when it is retracted from the cranks, and a manual member for rotating the nut.

6. In a radio receiving set, a tuning element, a shaft operatively connected thereto, sto means to limit the rotation of the shaft, a p urality of cranks on the shaft independently angularly adjustable thereon, a single manual operating member for the cranks slidable selectively into engagement therewith, a nut on the shaft operative to lock the cranks to the shaft, an abutment on the shaft frictionally engaged by the nut when it is re-. tracted, and a manual member for rotating the nut.

'7. In a radio receiving set, a tuning element, a movable member for operating the tuning element, a plurality of actuating members operativelyconnectible with the movable member and each adjustable in its relation thereto, manual means for selectively operating the actuating elements,.a manual devlce controlling the connections between the actuatin elements and the movable mem ber and-shi table to connect and disconnect the same, and means for operatively attaching the manual device to the movable member 5 when in position to disconnect the actuating elements.

In witness whereof, I hei'euntc subscribe my signature.

LOUIS H. MORIN. 

